Starter Alternator Troubleshooting Tips
Things to check before you pull your starter or alternator:
Alternator Troubleshooting:
- Alternator: Check the battery voltage with the engine running and not running. This can be done using a multimeter or a voltage meter. Measured across the battery terminals the voltage should be 12 volts +/- 1 volt with the engine off. With the engine running the voltage should be greater 13.8 and close 14 volts.
- Check for corrosion on the battery terminal connections. If the battery terminals are corroded the alternator could appear to have a low output, but actually just a bad connection. Disconnect and clean the battery terminals and connections with a wire brush and terminal cleaner (baking soda and water).
- Check the alternator drive belt. A loose or worn belt can significantly decrease the alternator output. If the belt is found to be loose or worn tighten the belt and/or replace with a new belt and then retest the voltage output of the alternator before pulling.
Starter Troubleshooting:
- First check the power supply connections from the battery. Loose or corroded connections can prevent the starter solenoid for engaging.
- The most common cause of starter failure is the solenoid. This is good to know because a solenoid can be replace at a fraction of the cost of a new starter. But you can not purchase a solenoid for you starter at most auto parts stores. This is one of the benefits of bringing your starter to me for testing to determine the problem.
